EP2967601B1

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Info

Publication number: EP2967601B1
Application number: EP14729091.0A
Authority: EP
Inventors: Chad J. Kugler; David B. Robinson
Original assignee: Scimed Life Systems Inc
Current assignee: Boston Scientific Scimed Inc
Priority date: 2013-03-14
Filing date: 2014-03-12
Publication date: 2017-11-29
Anticipated expiration: 2034-03-12
Also published as: US20180110537A1; US20140277068A1; US10806474B2; EP2967601A2; CN105208946B; US9878128B2; WO2014159549A3; CN105208946A; WO2014159549A2

Description

TECHNICAL FIELD

This disclosure relates to systems and devices for treating chronic occlusions in blood vessels and associated methods. More particularly, this disclosure relates to devices for establishing a blood flow path around a chronic total occlusion and methods for fabricating those devices.

BACKGROUND

A number of diseases are caused by the build-up of plaque in the arteries. These plaque deposits limit blood flow to the tissues that are supplied by that particular artery. When these deposits build up in the arteries of the heart, the problem is called coronary artery disease (CAD). When these deposits build up in the arteries of a limb, such as a leg, the condition is called peripheral artery disease (PAD).
Peripheral artery disease affects 8 to 12 million individuals in the United States and is also prevalent in Europe and Asia. Roughly 30% of the population over the age of 70 suffers from PAD. PAD typically causes muscle fatigue or pain brought about by exertion and relieved by rest. Symptoms of PAD can include leg pain during walking and wounds that do not heal. The inability to walk without leg pain often causes patients to stop exercising and reduces the patient's mobility. When the plaque builds up to the point where an artery is totally occluded, the obstruction is referred to as a Chronic Total Occlusion (CTO). A CTO that occludes the peripheral arteries for PAD patients is extremely serious. PAD patients that suffer from a CTO often enter a downward spiral towards death. Often the CTO in a peripheral artery results in limb gangrene, which requires limb amputation to resolve. The limb amputation in turn causes other complications, and roughly half of all PAD patients die within two years of a limb amputation.
The blood pumping action of the heart muscle is critical to sustaining the life of a patient. In order for the heart to function properly the tissues of the heart muscle must be continuously supplied and re-supplied with oxygen. To receive an adequate supply of oxygen, the heart muscle must be well perfused with blood. In a healthy heart, blood perfusion is accomplished with a system of arteries and capillaries. However, due to age, high cholesterol and other contributing factors, a large percentage of the population has arterial atherosclerosis that totally occludes portions of the patient's coronary arteries. A chronic total occlusion (CTO) in a coronary artery may cause painful angina, atrophy of cardiac tissue and patient death.
US 4,870,953 discloses an ultrasonic apparatus for the treatment of a patient having blood vessels obstructed by deposits of atherosclerotic plaque or blood clots, comprising: an ultrasonic energy source; an elongated, solid, flexible probe having first and second ends and coupled at the first end to the ultrasonic energy source and having a tip at the second end, the probe length selected so as to provide both longitudinal and transverse motion of the probe tip, the probe tip having a blunt, rounded shape formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip; a hollow catheter for internally carrying a portion of the probe, the catheter having first and second ends, the tip of the probe having a diameter less than the internal diameter of the hollow catheter; and means adapted to slide the probe within the catheter to extend the probe from the second end of the catheter into a mass of atherosclerotic plaque or blood clots.

SUMMARY

The disclosure is directed to several alternative designs, materials and methods of manufacturing medical device structures and assemblies, and uses thereof.
Accordingly, one illustrative embodiment is a system for treating a blood vessel including a blood vessel wall defining a blood vessel lumen where the blood vessel lumen is at least partially obstructed by an occlusion. The occlusion divides the lumen into a proximal lumen segment and a distal lumen segment. The system includes an orienting catheter and an occlusion catheter. The orienting catheter includes an orienting catheter shaft carrying an orienting element and a tracking element advanceable along the orienting catheter shaft. The occlusion catheter includes a balloon and a coupling element configured to engage a complementary coupling element of the tracking element to form a connection therebetween. The occlusion catheter defines an inflation lumen disposed in fluid communication with an interior of the balloon so that the balloon can be selectively inflated by injecting an inflation fluid through the inflation lumen. The balloon, when in an inflated state, is sized so as to occlude the blood vessel lumen to isolate a target volume defined by blood vessel tissues. The occlusion catheter defines an aspiration lumen disposed in fluid communication with a distal port positioned so that fluid can be withdrawn from the target volume and into the aspiration lumen.
Another illustrative embodiment is a method for treating a blood vessel including a blood vessel wall defining a blood vessel lumen, where the blood vessel lumen is at least partially obstructed by an occlusion. The occlusion divides the lumen into a proximal lumen segment and a distal lumen segment. The method includes positioning an orienting element of an orienting catheter inside an intrawall space located distal of the occlusion from the proximal lumen segment. The intrawall space is located between an intima and an adventitia of the blood vessel wall. An occluding element of an occlusion catheter is positioned in the proximal lumen segment at a location near the occlusion. The occluding element includes a balloon. The balloon of the occlusion catheter is inflated in the proximal lumen segment so as to isolate a target volume. The target volume includes the intrawall space. The pressure inside the target volume is reduced. The orienting element is deployed in the intrawall space so that the orienting catheter assumes an orientation in which a port of the orienting catheter is directed toward the distal lumen segment. A distal end of a reentry device is advanced from the port through the intima and into the distal lumen segment.
Yet another illustrative embodiment is a method for treating a blood vessel including a blood vessel wall defining a blood vessel lumen, where the blood vessel lumen is at least partially obstructed by an occlusion. The occlusion divides the lumen into a proximal lumen segment and a distal lumen segment. The method includes positioning an orienting element of an orienting catheter inside an intrawall space located distal of the occlusion from the proximal lumen segment. The intrawall space is located between an intima and an adventitia of the blood vessel wall. An occluding element of an occlusion catheter is positioned in the proximal lumen segment at a location near the occlusion. The occluding element includes a balloon. The balloon of the occlusion catheter is inflated in the proximal lumen segment so as to isolate a target volume. The target volume includes the intrawall space. The volume of the target volume is reduced so that the intima presses against the orienting element of the orienting catheter. The orienting element is deployed in the intrawall space so that the orienting catheter assumes an orientation in which a port of the orienting catheter is directed toward the distal lumen segment. The distal end of a reentry device is advanced from the port through the intima and into the distal lumen segment.
The above summary of some example embodiments is not intended to describe each disclosed embodiment or every implementation of the aspects of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a stylized anterior view showing a human patient. A portion of the patient's arterial system is schematically illustrated inFigure 1.
Figure 2A is an enlarged schematic view showing a portion of the arterial system of a patient who has been treated for peripheral artery disease (PAD).
Figure 2B is an enlarged schematic view showing a portion of the arterial system of a patient who has been treated for coronary artery disease (CAD).
Figure 3 is a stylized perspective view illustrating a blood vessel having a wall comprising three layers.
Figure 4 is an additional stylized perspective view of a blood vessel having a wall including an adventitia, a media, and an intima.
Figure 5 is a stylized drawing showing a human heart.
Figure 6 is a stylized depiction of a display screen that is part of a fluoroscopy system. InFigure 6 an angiographic image illustrating the vasculature of the heart is projected onto the display screen.
Figures 7A-7C diagramically illustrate exemplary situations that may disrupt a physician's ability to visualize a portion of a patient's vasculature.
Figure 8A is a stylized depiction of a heart including a blood vessel.
Figure 8B is a stylized depiction of a display screen that is part of a fluoroscopy system. InFigure 8B an angiographic image illustrating the blood vessel shown inFigure 8A is projected onto the display screen.
Figure 8C is an additional stylized depiction of the blood vessel and heart shown inFigure 8A.
Figure 8D is a stylized depiction of a display screen that is part of a fluoroscopy system. InFigure 8D an angiographic image illustrating the blood vessel shown inFigure 8C is projected onto the display screen.
Figure 9A is a perspective view showing an assembly including an orienting catheter and a re-entry device. The assembly ofFigure 9A may be used, for example, to establish a blood flow path between a proximal segment of a blood vessel and a distal segment of a blood vessel that are separated by an occlusion.
Figure 9B is an enlarged isometric view further illustrating a portion of the assembly shown inFigure 9A.
Figure 9C is a cross-section view taken along section line C-C shown inFigure 9A.
Figure 9D is a cross-section view taken along section line D-D shown inFigure 9A.
Figure 10 through Figure 22 are a series of stylized fragment views illustrating various steps that may be included as part of the methods in accordance with the detailed description. The apparatus described herein may be useful, for example, when performing these methods.
Figure 23 is a plan view showing a system that may be useful, for example, when establishing a blood flow path between a proximal segment of a blood vessel and a distal segment of a blood vessel that are separated by an occlusion. The system ofFigure 23 may also be used to facilitate visualization of a patient's vasculature using fluoroscopic techniques when conditions arise which interfere with the flow of radiopaque media.
Figure 24A is a plan view showing a system in accordance with the detailed description.
Figure 24B is an enlarged plan view further illustrating a portion of the system shown inFigure 24A.
Figure 25A is an additional plan view illustrating a second configuration of the system shown inFigures 24A-24B.
Figure 25B is an enlarged plan view further illustrating a portion of the system shown inFigure 25A.
Figure 26A is a plan view showing a system in accordance with the detailed description.
Figure 26B is an enlarged plan view further illustrating a portion of the system shown inFigure 26A.
Figure 27A is an additional plan view illustrating a second configuration of the system shown inFigures 26A-26B.
Figure 27B is an enlarged plan view further illustrating a portion of the system shown inFigure 27A.
Figure 28A is a stylized pictorial view of a blood vessel having a wall including an adventitia, a media, and an intima.
Figure 28B is an additional stylized pictorial view of the blood vessel shown inFigure 28A.

DETAILED DESCRIPTION

The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure.
Figure 1 is a stylized anterior view illustrating the cardiovascular system of a human patient. The cardiovascular system ofFigure 1 includes aheart 7 that pumps blood and an arterial system that distributes oxygen rich blood throughout the body. During each heartbeat, the left ventricle ofheart 7 contracts, pumping blood through the aortic valve and into the ascendingaorta 74. Blood from the ascendingaorta 74 flows through theaortic arch 76 and down the descendingaorta 12 to the lower body. Blood from the ascendingaorta 74 also flows into the leftcoronary artery 70B and the rightcoronary artery 70A. In a healthy heart, the leftcoronary artery 70B and the rightcoronary artery 70A provide a continuous flow of blood to the heart which assures that the heart muscle remains well oxygenated.
The descendingaorta 12 gives off numerous branches that supply oxygenated blood to the chest cage and the organs within the chest. The descendingaorta 12 continues to theiliac bifurcation 30, which is a branch that splits into the two commoniliac arteries 16A and 16B. The iliac arterial vasculature includes two branches continuing from theiliac bifurcation 30. The right branch includes the right commoniliac artery 16A, which bifurcates into the right externaliliac artery 25A and the right internaliliac artery 27A. When the right externaliliac artery 25A passes posterior to the inguinal ligament, it becomes the rightfemoral artery 29A of the right leg. The left branch of the iliac arterial vasculature includes the left commoniliac artery 16B, which bifurcates into the left externaliliac artery 25B and the left internaliliac artery 27B. When the left externaliliac artery 25B passes posterior to the inguinal ligament, it becomes the leftfemoral artery 29B of the left leg.
In the exemplary embodiment ofFigure 1, anocclusion 32 is blocking blood flow through a portion of a blood vessel within a target region T of the patient's arterial system. Theocclusion 32 is obstructing blood flow between aproximal segment 120 of the blood vessel and adistal segment 138 of the blood vessel. A system in accordance with the present detailed description may be used to establish a blood flow path betweenproximal segment 120 anddistal segment 138.
Figure 2A is an enlarged schematic view showing a portion of the arterial system of a patient who has been treated for peripheral artery disease (PAD). The portion of the arterial system shown inFigure 2A includes the descendingaorta 12, theiliac bifurcation 30, the right commoniliac artery 16A and the left commoniliac artery 16B. In the exemplary embodiment ofFigure 2A, the patient's condition has been treated by establishing a blood flow path around anocclusion 32. The blood flow aroundocclusion 32 is illustrated using arrows inFigure 2A. The portion of the arterial system located in target region T may be treated using a contralateral approach. When using the contralateral approach, an endovascular device may enter the vascular system at an access point P. After entering the arterial system the endovascular device may be advanced throughiliac bifurcation 30 to reach the target region T in the leg opposite the leg that is the site of access. In other instances, another approach may be used to reach the target region T.
Figure 2B is an enlarged schematic view showing a portion of the arterial system of a patient who has been treated for coronary artery disease (CAD). The portion of the arterial system shown inFigure 2B includes theaortic valve 72, the rightcoronary artery 70A, the leftcoronary artery 70B, the ascendingaorta 74, and theaortic arch 76. Leftcoronary artery 70B and rightcoronary artery 70A each meet the ascendingaorta 74 at an ostium. During the systolic phase of each cardiac cycle, oxygen rich blood from the ascendingaorta 74 flows through leftcoronary artery 70B and rightcoronary artery 70A. In a healthy heart, this oxygen rich blood is distributed throughout the heart by a network of arteries and capillaries.
In the exemplary embodiment ofFigure 2B, the patient's condition has been treated by establishing a blood flow path around anocclusion 32. The blood flow aroundocclusion 32 is illustrated using arrows inFigure 2B. In the exemplary embodiment ofFigure 2B,occlusion 32 is located in leftcoronary artery 70B. The methodology for treating a coronary artery may include inserting a guide catheter into a femoral artery and advancing the guide catheter such that its distal tip moves through that artery, up the descending aorta, through the aortic arch and ultimately into the ostium of the coronary artery. A system in accordance with this detailed description may then be advanced through the guide catheter into the coronary artery. Once in the coronary artery, the system may be used to establish a blood flow path between a proximal segment of the coronary artery and a distal segment of the coronary artery. In other instances, another approach may be used to treat the coronary artery.
Figure 3 is a stylized perspective view illustrating ablood vessel 30 having awall 40. InFigure 3,wall 40 ofblood vessel 30 is shown having three layers. The outermost layer ofwall 40 is theadventitia 42 and the innermost layer ofwall 40 is theintima 44.Intima 44 defines atrue lumen 34 ofblood vessel 30. The tissues extending betweenintima 44 andadventitia 42 may be collectively referred to as the media M. For purposes of illustration,intima 44, media M andadventitia 42 are each shown as a single homogenous layer inFigure 3. In the human body, however, theintima 44 and the media M each comprise a number of sub-layers. The transition between the external most portion of theintima 44 and the internal most portion of the media M is sometimes referred to as the subintimal space. In the embodiment ofFigure 3, anocclusion 32 is blocking thetrue lumen 34 ofblood vessel 30.Occlusion 32 dividestrue lumen 34 into aproximal lumen segment 36 and adistal lumen segment 38.
Figure 4 is an additional stylized perspective view of ablood vessel 30 having awall 40 including anadventitia 42, a media M, and anintima 44. In the embodiment ofFigure 4, a portion ofintima 44 has become separated from the other layers ofblood vessel wall 40. This situation may occur, for example, when a physician has passed one or more prolapsed guidewires, or other medical device, betweenintima 44 andadventitia 42. A prolapsed guidewire is a guidewire having a distal tip that has been bent to form a loop or knuckle. The human heart includes a number of blood vessels having the general structure illustrated inFigure 4. Examples of these blood vessels include the left coronary artery and the right coronary artery.
Figure 5 is a stylized drawing showing a human heart. The heart ofFigure 5 includes a plurality of coronary arteries, all of which are susceptible to occlusion. Under certain physiological circumstances and given sufficient time, some occlusions may become total or complete. As used herein, the terms total occlusion and complete occlusion are intended to refer to the same or similar degree of occlusion with some possible variation in the age of the occlusion. Generally, a total occlusion refers to a vascular lumen that is ninety percent or more functionally occluded in cross-sectional area, rendering it with little to no blood flow therethrough and making it difficult or impossible to pass a conventional guide wire therethrough. Also generally, the older the total occlusion the more organized the occlusive material will be and the more fibrous and calcified it will become. According to one accepted clinical definition, a total occlusion is considered chronic if more than two weeks have passed since the onset of symptoms.
Methods and apparatus disclosed in this detailed description may be useful, for example, to establish a blood flow path around an occlusion (e.g., a total occlusion) in a blood vessel. Methods and apparatus disclosed in this detailed description may also be used to facilitate visualization of a patient's vasculature using fluoroscopic techniques. Fluoroscopy is a medical imaging technique used by physicians to obtain real-time moving images of the internal structures of a patient through the use of a fluoroscope. During a procedure utilizing fluoroscopy, a radio-opaque contrast agent is injected into the blood stream in a selected area of the patient's vasculature. This causes blood flowing through the selected areas to become visible on a display screen.
Figure 6 is a stylized depiction of a display screen FD that is part of a fluoroscopy system. InFigure 6 an angiographic image AI illustrating the vasculature of the heart is projected onto display screen FD. Fluoroscopic systems that may be suitable in some applications are commercially available from GE Heathcare (Chalfont, St. Giles, UK) and Siemens (Munchen, Bayern, DE).
A physician's ability to visualize a portion of a patient's vasculature may be disrupted during some medical procedures. In some cases, this disruption may make it difficult or impossible for the physician to successfully complete the procedure.Figures 7A-7C are somewhat symbolic diagrams illustrating exemplary situations that may disrupt a physician's ability to visualize a portion of a patient's vasculature.
Figure 7A is a stylized diagram showing a portion of ablood vessel 30 that is being treated by a physician. InFigure 7A, anocclusion 32 can be seen dividingtrue lumen 34 ofblood vessel 30 into aproximal lumen segment 36 and adistal lumen segment 38.Proximal lumen segment 36 is generally in fluid communication with the left ventricle of the heart.Distal lumen segment 38 is generally in fluid communication with the right atrium of the heart. As the left ventricle pumps blood intoproximal segment 36, the fluid in that area of theblood vessel 30 will have a ventral pressure PV. At the same time, the blood indistal segment 38 will have an atrial pressure PA. Due to the blood pumping action of the heart, ventral pressure PV is generally greater than atrial pressure PA. Accordingly, it will be appreciated that there is a pressure differential acrossocclusion 32 in the embodiment ofFigure 7A.
In the embodiment ofFigure 7B, a physician has created an intrawall space S extending betweenintima 44 andadventitia 42 ofblood vessel wall 40. Intrawall space S may be created, for example, by moving one or more prolapsed guidewires, or other medical device, betweenintima 44 andadventitia 42. A prolapsed guidewire may also be moved betweenocclusion 32 andadventitia 42, thereby establishing fluid communication betweenproximal lumen segment 36 and intrawall space S. In the embodiment ofFigure 7B, blood fromproximal lumen segment 36 has filled intrawall space S.
In the embodiment ofFigure 7B, the blood inside intrawall space S is generally at ventricle pressure PV and the blood insidedistal lumen segment 38 is generally at atrial pressure PA. Accordingly, there is a pressure differential acrossintima 44 in the embodiment ofFigure 7B. This pressure differential has caused intrawall space S to fill with blood fromproximal lumen segment 36 in the embodiment ofFigure 7B.
Figure 7C is an additional stylized representation ofblood vessel 30 and intrawall space S. By comparingFigure 7C withFigure 7B, it will be appreciated that the length L of intrawall space S has become greater. In the exemplary embodiment ofFigure 7C, the pressure differential acrossintima 44 has caused additional dissection of the blood vessel wall. In some cases, the length of a dissection can grow in this way even when that is not the result desired or intended by the physician. As further illustrated inFigure 8, an elongated dissection can interfere with the physician's ability to "see" a portion of the vasculature using fluoroscopic techniques.
Figure 8A is a stylized depiction of a heart H including ablood vessel 30. In the embodiment ofFigure 8A, anocclusion 32 is blocking thetrue lumen 34 ofblood vessel 30.Occlusion 32 dividestrue lumen 34 into aproximal lumen segment 36 and adistal lumen segment 38. During a surgical procedure, a physician may wish to viewproximal lumen segment 36 anddistal lumen segment 38 ofblood vessel 30 using fluoroscopic techniques.
When using fluoroscopic techniques, the physician may inject a radio-opaque contrast agent into the blood stream in the areas nearocclusion 32. The radio-opaque contrast agent may be injected into the lumen ofblood vessel 30 from both an antegrade direction A and a retrograde direction R. Antegrade direction A and a retrograde direction R are both represented with arrows inFigure 8A.
Figure 8B is a stylized depiction of a display screen FD that is part of a fluoroscopy system. InFigure 8B an angiographic image AI illustratingblood vessel 30 ofFigure 8A is projected onto display screen FD. The radio-opaque contrast agent insideblood vessel 30 has madeproximal lumen segment 36 anddistal lumen segment 38 visible on display screen FD.
Figure 8C is an additional stylized depiction ofblood vessel 30 and heart H shown inFigure 8A. In the embodiment ofFigure 8C, a physician has created an intrawall space S extending betweenintima 44 andadventitia 42 ofblood vessel 30. Intrawall space S may be created, for example, by moving one or more prolapsed guidewires, or other medical device, betweenintima 44 andadventitia 42. A prolapsed guidewire may also be moved betweenocclusion 32 andadventitia 42, thereby establishing fluid communication betweenproximal lumen segment 36 and intrawall space S. In the embodiment ofFigure 8C, blood fromproximal lumen segment 36 has filled intrawall space S. Also in the embodiment ofFigure 8C, there is a pressure differential acrossintima 44 between intrawall space S anddistal segment 38. This pressure differential is due to the fact that the blood inside the true lumen distal ofocclusion 32 is generally at atrial pressure PA and the blood inside intrawall space S is at ventral pressure PV.
Any radio-opaque contrast agent traveling in the retrograde direction R insidetrue lumen 34 ofblood vessel 30 is unlikely to reach the area ofdistal lumen segment 38 nearest toocclusion 32 because this area of thetrue lumen 34 is occupied by intrawall space S. Additionally, any radio-opaque contrast agent travelling in the antegrade direction A insidetrue lumen 34 ofblood vessel 30 is unlikely to enter intrawall space S because no blood is leaving intrawall space S to make room for the entering fluid. If no radio-opaque contrast agent enters intrawall space S, then that area of the vasculature cannot be displayed using fluoroscopic techniques.
Figure 8D is a stylized depiction of a fluoroscopic display screen FD. InFigure 8D an angiographic image AI illustratingblood vessel 30 ofFigure 8C is projected onto display screen FD. By comparingFigure 8D withFigure 8B, it will be appreciated that a substantial portion ofdistal lumen segment 38 is not visible in angiographic image AI. The portion ofblood vessel 30 that is not displayed in angiographic image AI generally corresponds to the portion ofdistal lumen segment 38 that is occupied by intrawall space S.
Figure 9A is a perspective view showing anassembly 90 including orientingcatheter 200 andre-entry device 100.Assembly 90 may be used, for example, to establish a blood flow path between a proximal segment of a blood vessel and a distal segment of a blood vessel that are separated by a chronic total occlusion.Figure 9B is an enlarged isometric view further illustrating a portion ofassembly 90.
Orientingcatheter 200 ofFigure 9A comprises ashaft assembly 202 and an orientingelement 204, such as an orienting balloon, that is carried byshaft assembly 202. Orientingelement 204 is capable of assuming both a collapsed shape and an expanded shape. Orientingelement 204 may be selectively placed in the collapsed shape, for example, while the orientingelement 204 is being advanced past an occlusion. Orientingelement 204 may be selectively placed in the expanded shape, for example, while the orientingcatheter 200 is being used todirect re-entry device 100 toward the lumen of a blood vessel. Orientingelement 204 is shown assuming the expanded shape.
Orientingelement 204 of orientingcatheter 200 comprises afirst portion 206 and asecond portion 208. In the embodiment ofFigure 9B,first portion 206 of orientingelement 204 comprises a firstinflatable member 220.Second portion 208 of orientingelement 204 comprises a secondinflatable member 224 in the embodiment ofFigure 9B.
Firstinflatable member 220 of orientingelement 204 extends in afirst direction 20 away fromlongitudinal axis 222 ofshaft assembly 202. Secondinflatable member 224 of orientingelement 204 extends away fromlongitudinal axis 222 ofshaft assembly 202 in asecond direction 22.First direction 20 andsecond direction 22 are represented with arrows inFigure 9A. With reference toFigure 9A, it will be appreciated thatsecond direction 22 is generally oppositefirst direction 20. InFigure 9A, the arrows representingfirst direction 20 andsecond direction 22 are directed about 180 degrees away from one another.
Shaft assembly 202 ofFigure 9A defines afirst aperture 226 and a second aperture 228 (shown inFigure 9B). In the embodiment ofFigure 9A,first aperture 226 extends away fromcentral lumen 230 in athird direction 24.Second aperture 228 extends away fromcentral lumen 230 in afourth direction 26.Third direction 24 andfourth direction 26 are represented with arrows inFigure 9A. In the embodiment ofFigure 9A,third direction 24 andfourth direction 26 extend in generally opposite directions. InFigure 9A, the arrows representingthird direction 24 andfourth direction 26 are directed about 180 degrees away from each other and perpendicular to the first andsecond directions 20, 22.
Ahub 236 is fixed to the proximal end ofshaft assembly 202.Hub 236 includes aninflation port 238.Inflation port 238 fluidly communicates with an interior of firstinflatable member 220 and secondinflatable member 224 via inflation lumens IL defined byshaft assembly 202. Theinflatable members 220, 224 may be inflated by injecting an inflation media intoinflation port 238. Examples of inflation media that may be suitable in some applications include saline, carbon dioxide, and nitrogen.
Orientingcatheter 200 defines aproximal port 232, adistal port 234 and acentral lumen 230 that extends betweenproximal port 232 anddistal port 234. In the embodiment ofFigure 9A,proximal port 232 is defined byhub 236 anddistal port 234 is defined byshaft assembly 202.Re-entry device 100 may be inserted intoproximal port 232, advanced alongcentral lumen 230, and advanced through any one ofdistal port 234,first aperture 226 andsecond aperture 228.
Figure 9C is a cross-section view ofassembly 90 taken along section line C-C shown inFigure 9A. With reference toFigure 9C, it will be appreciated thatre-entry device 100 may comprise acore wire 104 that is disposed in acentral lumen 230 defined byshaft assembly 202 of orientingcatheter 200.Figure 9D is a cross-section view ofassembly 90 taken along section line D-D shown inFigure 9A. With reference toFigure 9D, it will be appreciated that the distal portion ofshaft assembly 202 defines acentral lumen 230.Core wire 104 ofre-entry device 100 can be seen residing incentral lumen 230 inFigure 9D.
Figure 10 through Figure 22 are a series of stylized pictorial views illustrating various steps that may be included as part of the methods in accordance with this detailed description. Methods and apparatus in accordance with the present detailed description may be used, for example, to establish a blood flow path around an occlusion in a blood vessel.
Figure 10 is a longitudinal cross-sectional view of ablood vessel 30 having anocclusion 32 blocking thetrue lumen 34 thereof.Occlusion 32 dividestrue lumen 34 into aproximal lumen segment 36 and adistal lumen segment 38. InFigure 10, a distal portion of acrossing device 150 is shown extending intoproximal lumen segment 36 oftrue lumen 34.Crossing device 150 may be advanced over a guidewire to the position shown inFigure 10. In the embodiment ofFigure 10, crossingdevice 150 comprises atip 152 that is fixed to a distal end of ashaft 154.Tip 152 can be seen residing inproximal lumen segment 36 oftrue lumen 34 inFigure 10.
Figure 11 is an additional longitudinal cross-sectional view ofblood vessel 30. By comparingFigure 11 with the previous figure, it will be appreciated thattip 152 of crossingdevice 150 has been advanced in a distal direction D. Distal direction D is illustrated using an arrow inFigure 11. In the embodiment ofFigure 11,tip 152 of crossingdevice 150 is disposed in a position betweenocclusion 32 andadventitia 42 ofblood vessel wall 40.Tip 152 is shown disposedadjacent occlusion 32 inFigure 11. With reference toFigure 11, it will be appreciated that crossingdevice 150 extends throughintima 44 to the position betweenocclusion 32 andadventitia 42 ofblood vessel 30.
Figure 12 is an additional view ofblood vessel 30 andcrossing device 150 shown in the previous figure. In the embodiment ofFigure 12,tip 152 of crossingdevice 150 has been advanced in distal direction D so thattip 152 is disposed at a location distal ofocclusion 32. In the embodiment ofFigure 12, crossing device has moved in distal direction D betweenintima 44 andadventitia 42 as it has advanced distally beyondocclusion 32.
With reference to the sequence of three figures described immediately above, it will be appreciated that methods in accordance with the present detailed description may include the step of advancing a crossing device along a blood vessel to a location near an occlusion. The crossing device may be advanced over a guidewire that has been previously advanced to that location. These methods may also include the step of advancing the distal end of a crossing device (e.g., crossing device 150) between an occlusion and the adventitia of a blood vessel. The crossing device may be advanced beyond the occlusion to establish a blood flow path between a proximal segment on one side of the occlusion and a distal segment on the other side of the occlusion. For example, the crossing device may re-enter the lumen of the blood vessel as it moves past the occlusion. In some cases, the crossing device may advance distally between the intima and the adventitia of the blood vessel. As the tip of the crossing device moves in a distal direction between the intima and the adventitia, the tip may cause blunt dissection of the layers forming the wall of the blood vessel. If the tip of the crossing device does not spontaneously or automatically enter the lumen, a system in accordance with this detailed description may be used to pierce the intima and re-enter the lumen of the blood vessel.
In some useful methods in accordance with this detailed description, the crossing device may be rotated about its longitudinal axis and moved in a direction parallel to its longitudinal axis simultaneously. When this is the case, rotation of the crossing device may reduce resistance to the axial advancement of the crossing device. These methods take advantage of the fact that the kinetic coefficient of friction is usually less than the static coefficient of friction for a given frictional interface. Rotating the crossing device assures that the coefficient of friction at the interface between the crossing device and the surrounding tissue will be a kinetic coefficient of friction and not a static coefficient of friction. The rotating action may also change the direction of force vectors representing the effect of friction on the device.
Rotation of the crossing device can be achieved by rolling a handle portion of the crossing device between the thumb and forefinger of one hand, for example. Two hands may also be used to rotate the crossing device. In some useful methods in accordance with this detailed description, the crossing device is rotated at a rotational speed of between about 2 revolutions per minute and about 200 revolutions per minute. In some particularly useful methods in accordance with this detailed description, the crossing device is rotated at a rotational speed of between about 50 revolutions per minute and about 150 revolutions per minute. The crossing device may be rotated at a rotational speed that is sufficient to assure that the coefficient of friction at the interface between the crossing device and the surrounding tissue will be a kinetic coefficient of friction and not a static coefficient of friction. It is also contemplated that a mechanical device (e.g., an electric motor) may be used to rotate the crossing device.
Figure 13 is an additional stylized pictorial view ofblood vessel 30 andcrossing device 150 shown in the previous figure. In the embodiment ofFigure 13,tip 152 of crossingdevice 150 is disposed at a location distal ofocclusion 32.Tip 152 can be seen resting in an intrawall space S between theintima 44 and theadventitia 42 ofblood vessel 30 inFigure 13.
Figure 14 is an additional stylized pictorial view ofblood vessel 30 shown in the previous figure. By comparingFigure 14 with the previous figure, it will be appreciated that aguidewire 999 may remain in the position formerly occupied by crossingdevice 150. With reference toFigure 14, it will be appreciated thatguidewire 999 may rest inside intrawall space S between theintima 44 and theadventitia 42 ofblood vessel 30.
In the embodiment ofFigure 14, crossingdevice 150 has been withdrawn fromblood vessel 30 whileguidewire 999 has remained in the position shown inFigure 14. The position ofguidewire 999 shown inFigure 14 may be achieved, for example, by first placingcrossing device 150 in the position shown in the previous figure, then advancingguidewire 999 through a lumen defined byshaft 154 of crossingdevice 150. Alternately, guidewire 999 may be disposed within the lumen ofshaft 154 while crossingdevice 150 is advanced beyondocclusion 32. Withguidewire 999 in the position shown inFigure 14, guidewire 999 may be used to direct other endovascular devices into the intrawall volume betweenocclusion 32 andadventitia 42. Examples of endovascular devices that may be advanced overguidewire 999 include balloon catheters, atherectomy catheters, and stent delivery catheters.
Figure 15 is an additional stylized pictorial view ofblood vessel 30 shown in the previous figure. InFigure 15, an orientingcatheter 200 is shown residing in the intrawall space previously occupied byguidewire 999. Orientingcatheter 200 may be advanced into the position shown inFigure 15, for example, by advancing orientingcatheter 200 overguidewire 999 shown in the previous figure. Orientingcatheter 200 comprises ashaft assembly 202 and an orientingelement 204 that is carried byshaft assembly 202. Orientingelement 204 may be capable of assuming both a collapsed shape and an expanded shape. Orientingelement 204 may be selectively placed in the collapsed shape, for example, while the orienting element is being advanced past an occlusion (e.g.,occlusion 32 shown inFigure 15). Orientingelement 204 may be selectively placed in the expanded shape, for example, while the orientingcatheter 200 is being used to direct a re-entry device toward the lumen of a blood vessel. InFigure 15, orientingelement 204 is shown assuming the expanded shape.
Orientingelement 204 of orientingcatheter 200 comprises afirst portion 206 and asecond portion 208. In some instances, orientingelement 204 may be an inflatable balloon. In the embodiment ofFigure 15,first portion 206 of orientingelement 204 comprises a firstinflatable member 220.Second portion 208 of orientingelement 204 comprises a secondinflatable member 224 in the embodiment ofFigure 15. Firstinflatable member 220 of orientingelement 204 extends in afirst direction 20 away fromlongitudinal axis 222 ofshaft assembly 202. Secondinflatable member 224 of orientingelement 204 extends away fromlongitudinal axis 222 ofshaft assembly 202 in asecond direction 22 that is generally opposite the first direction.Shaft assembly 202 defines adistal port 234, a proximal port (not shown inFigure 15) and a central lumen extending between the distal port and the proximal port.
Figure 16 is an additional stylized pictorial view ofblood vessel 30 and orientingcatheter 200 shown in the previous figure. InFigure 16, a distal portion of anocclusion catheter 300 can be seen residing inproximal lumen segment 36 oftrue lumen 34.Occlusion catheter 300 includes aballoon 302 carried by ashaft assembly 304.Shaft assembly 304 defines anaspiration lumen 308 ending at adistal aspiration port 306. With reference toFigure 16, it will be appreciated thatballoon 302 ofocclusion catheter 300 is disposed at a location slightly proximal ofocclusion 32. In some cases,occlusion catheter 300 may be positioned by advancing it over a guidewire. In other cases, it may be desirable to useorientation catheter 200 as a guide. When this is the case, a tracking element may be coupled to both orientingcatheter 200 andocclusion catheter 300. The tracking element may be adapted and configured to slide in distal and proximal axial directions alongshaft assembly 202 of orientingcatheter 200. The tracking element may be coupled toocclusion catheter 300 in a manner that precludes relative axial movement betweenshaft assembly 304 and the tracking element.
Figure 17 is an additional stylized pictorial view ofblood vessel 30 andocclusion catheter 300 shown in the previous figure. InFigure 17,balloon 302 ofocclusion catheter 300 is shown in an inflated state. In some useful embodiments,balloon 302 is adapted and dimensioned so as to occlude a blood vessel lumen when it assumes its inflated shape. In the embodiment ofFigure 17,balloon 302 has isolated a target volume T by occludingproximal lumen segment 36. The target volume T includes a portion ofproximal lumen segment 36 extending betweenballoon 302 andocclusion 32 in the embodiment ofFigure 17. Target volume T also includes the intrawall space S occupied byorientation catheter 200.
With target volume T isolated, fluid may be withdrawn from the target volume T by drawing the fluid throughdistal aspiration port 306 and intoaspiration lumen 308. Fluid may also be withdrawn from target volume T by drawing the fluid throughcentral lumen 230 of orientingcatheter 200. Withdrawing fluid from target volume T may reduce the pressure inside the target volume T (e.g., reduce the pressure inside the target volume T below ventral pressure PV) so that pressure insidedistal lumen segment 38 presses theintima 44 of theblood vessel 30 against the orientingelement 202 of orientingcatheter 200. The pressure within the target volume T may be reduced to be less than the pressure within the distal lumen segment 38 (e.g., atrial pressure PA). Withdrawing fluid from the target volume may be particularly beneficial when the blood vessel wall has been dissected as one or more prolapsed guidewires, or other medical device, have passed through it. More particularly, withdrawing fluid from the target volume may facilitate the use of fluoroscopic imaging techniques when an elongated dissection is interfering with the flow of radiopaque imaging media into a lumen segment of the blood vessel. Additionally, withdrawing fluid from the intrawall space S may facilitate the piercing ofintima 44 to complete a blood flow path extending between a proximal lumen segment and a distal lumen segment of the blood vessel.
Figure 18 is an additional stylized pictorial view ofblood vessel 30 and orientingcatheter 200 shown in the previous figure. For purposes of illustration, orientingcatheter 200 is shown in cross-section inFigure 18. With reference toFigure 18, it will be appreciated thatguidewire 999 has been withdrawn from acentral lumen 230 of orientingcatheter 200. Orientingcatheter 200 comprises ashaft assembly 202 defining afirst aperture 226 and asecond aperture 228. In the embodiment ofFigure 18,first aperture 226 extends away fromcentral lumen 230 in athird direction 24.Second aperture 228 extends away fromcentral lumen 230 in afourth direction 26 that is illustrated using an arrow inFigure 18.Third direction 24 is also represented with an arrow inFigure 18. In the embodiment ofFigure 18,third direction 24 andfourth direction 26 extend in generally opposite directions. InFigure 18, the arrows representingthird direction 24 andfourth direction 26 are directed about 180 degrees away from one another.
Orientingcatheter 200 includes an orientingelement 204, such as an orienting balloon, that is carried byshaft assembly 202. Orientingelement 204 is shown assuming an expanded shape inFigure 18. Orientingelement 204 is also capable of assuming a collapsed shape. Orientingelement 204 is dimensioned such that, when the orienting element assumes an expanded shape within the blood vessel wall, the shaft assembly will assume an arbitrary one of two possible orientations relative to the blood vessel lumen. The two possible orientations comprise a first orientation and a second orientation. In the exemplary embodiment ofFigure 18,first aperture 226 is positioned so as to open toward the blood vessel lumen whenshaft assembly 202 is assuming the first orientation within the blood vessel wall.Second aperture 228 is positioned so as to open toward the blood vessel lumen whenshaft assembly 202 is assuming the second orientation within the blood vessel wall. In the embodiment ofFigure 18 orientingcatheter 200 is oriented so thatsecond aperture 228 opens towardintima 44 ofblood vessel 30 andfirst aperture 226 opens away fromintima 44. Therefore, it will be appreciated that orienting device is assuming the second orientation.
In the embodiment ofFigure 18,first aperture 226 andsecond aperture 228 are longitudinally separated from one another, although other configurations are contemplated. Orientingcatheter 200 includes a firstradiopaque marker 240 that is located betweenfirst aperture 226 andsecond aperture 228. A secondradiopaque marker 242 of orientingcatheter 200 is located distally ofsecond aperture 228.
InFigure 18, anocclusion 32 is shown blockinglumen 34 ofblood vessel 30.Occlusion 32 prevents blood from flowing throughblood vessel 30. Fluid communication between a proximal segment ofblood vessel lumen 34 and a distal segment ofblood vessel lumen 34 may be achieved by re-entering the lumen with a re-entry device. Orientingcatheter 200 may be used to direct the re-entry device towardtrue lumen 34 to complete a blood flow path extending aroundocclusion 32.
Figure 19 is an additional stylized pictorial view ofblood vessel 30 and orientingcatheter 200 shown in the previous figure. In the embodiment ofFigure 19, are-entry device 100 has been advanced intocentral lumen 230 of orientingcatheter 200. With reference toFigure 19, it will be appreciated thatre-entry device 100 may include abend 142. In the embodiment ofFigure 19,re-entry device 100 is biased to assume a bent shape. Also in the embodiment ofFigure 19, the wall ofshaft assembly 202 is holdingre-entry device 100 in a somewhat deflected state. When this is the case,re-entry device 100 can be inserted throughsecond aperture 228 by positioning the distal end ofre-entry device 100 oversecond aperture 228 and allowingbend 142 to assume it's natural state (i.e., bent at a sharper angle). In the embodiment ofFigure 19, rotatingre-entry device 100 withincentral lumen 230 of orientingcatheter 200 will cause the distal end ofre-entry device 100 to entersecond aperture 228.
A physician may use a fluoroscopic display for guidance when placing the distal end of there-entry device 100 in general alignment with a selected aperture. When using fluoroscopic guidance,re-entry device 100, firstradiopaque marker 240, and secondradiopaque marker 242 will all be brightly displayed by the fluoroscopy system. When the physician positions the distal end ofre-entry device 100 slightly proximal of firstradiopaque marker 240, the physician may infer that the distal end ofre-entry device 100 is at a longitudinal position (i.e., a position along longitudinal axis 222) that is in general alignment withfirst aperture 226. The physician may then rotatere-entry device 100 so that the distal end ofre-entry device 100 entersfirst aperture 226. The distal end ofre-entry device 100 may then be advanced throughfirst aperture 226. The physician may observe the direction that a distal portion ofre-entry device 100 travels as it passes throughfirst aperture 226. From these fluoroscopic observations, the physician can determine whether the distal end of there-entry device 100 is directed toward the vascular lumen or directed away from the vascular lumen. If it is determined that there-entry device 100 is directed toward the vascular lumen, then there-entry device 100 can be advanced so that the distal end ofre-entry device 100 travels through the intima to a position inside thelumen 34 ofblood vessel 30. If it is determined that there-entry device 100 is directed away from the vascular lumen, then there-entry device 100 can be withdrawn fromfirst aperture 226 so that there-entry device 100 is again located within orientingcatheter 200. At this point, the physician may determinesecond aperture 228 should be used for re-entry on this particular occasion.
When the physician positions the distal end ofre-entry device 100 between firstradiopaque marker 240 and secondradiopaque marker 242, the physician may infer that the distal end ofre-entry device 100 is at a longitudinal position (i.e., a position along longitudinal axis 222) that is in general alignment withsecond aperture 228. The physician may then rotatere-entry device 100 so that the distal end ofre-entry device 100 enterssecond aperture 228. The distal end ofre-entry device 100 may then be advanced throughsecond aperture 228. The physician may observe the direction that a distal portion ofre-entry device 100 travels as it passes throughsecond aperture 228. From these fluoroscopic observations, the physician can confirm that the distal end of there-entry device 100 is directed toward thevascular lumen 34. If it is confirmed that there-entry device 100 is directed toward thevascular lumen 34, then there-entry device 100 can be advanced so that the distal end ofre-entry device 100 travels through theintima 44 to a position inside thelumen 34 ofblood vessel 30. It is contemplated that other structures/configurations may be utilized to cause/allow there-entry device 100 to pass from the orientingcatheter 200 for re-entry into thevascular lumen 34.
Figure 20 is an additional stylized pictorial view showingre-entry device 100 and orientingcatheter 200 shown in the previous figure. By comparingFigure 20 and the previous figure, it will be appreciated thatre-entry device 100 has been rotated so that a distal portion ofre-entry device 100 has enteredsecond aperture 228. With reference toFigure 20, it will be appreciated thatre-entry device 100 may comprise adistal surface 108 and aprobe 106 extending beyonddistal surface 108. In the embodiment ofFigure 20,probe 106 ofre-entry device 100 is contactingintima 44 ofblood vessel 30.Re-entry device 100 is shown extending distally throughcentral lumen 230 andsecond aperture 228 in the embodiment ofFigure 20. By advancingre-entry device 100 further in the distal direction D,re-entry device 100 can be advanced throughsecond aperture 228 and throughintima 44.
Figure 21 is an additional stylized pictorial view showingre-entry device 100 and orientingcatheter 200 shown in the previous figure. In the embodiment ofFigure 21,re-entry device 100 has been advanced further in distal direction D and probe 106 ofre-entry device 100 has pierced the surface ofintima 44. Probe 106 can be seen extending intointima 44 inFigure 21.Intima 44 may be weakened when pierced byprobe 106 as shown inFigure 21.Probe 106 may also function to anchor the distal tip ofre-entry device 100 to intima 44 so that the distal tip is less likely to slide along theintima 44 when pushing forces are applied to the proximal end ofre-entry device 100. The anchoring and weakening functions described above may aid a physician in advancingre-entry device 100 throughintima 44.
Figure 22 is an additional stylized pictorial view showingre-entry device 100 and orientingcatheter 200 shown in the previous figure. In the embodiment ofFigure 22, a distal portion ofre-entry device 100 has been advanced throughintima 44. With reference toFigure 22, it will be appreciated thatdistal surface 108 ofre-entry device 100 is disposed in thelumen 34 ofblood vessel 30. Probe 106 ofre-entry device 100 can be seen extending beyonddistal surface 108.Re-entry device 100 has piercedintima 44 creating a hole extending through theintima 44. A blood flow path extending aroundocclusion 32 is completed whenre-entry device 100 piercesintima 44.
Figure 23 is a plan view showing asystem 400 in accordance with the present detailed description.System 400 ofFigure 23 may be useful, for example, when establishing a blood flow path between a proximal segment of a blood vessel and a distal segment of a blood vessel that are separated by an occlusion (e.g., the subject matter illustrated in the preceding series of figures).System 400 may also be used to facilitate visualization of a patient's vasculature using fluoroscopic techniques when conditions arise which interfere with the flow of radiopaque media.
Orientingcatheter 200 ofFigure 23 comprises ashaft assembly 202 and an orientingelement 204, such as an orienting balloon, that is carried byshaft assembly 202. Orientingelement 204 is capable of assuming both a collapsed shape and an expanded shape. Orientingelement 204 may be selectively placed in the collapsed shape, for example, while the orientingelement 204 is being advanced past an occlusion. Orientingelement 204 may be selectively placed in the expanded shape, for example, while the orientingcatheter 200 is being used todirect re-entry device 100 toward the lumen of a blood vessel. InFigure 23, orientingelement 204 is shown assuming the expanded shape.
Orientingelement 204 of orientingcatheter 200 comprises afirst portion 206 and asecond portion 208. In the embodiment ofFigure 23,first portion 206 of orientingelement 204 comprises a firstinflatable member 220.Second portion 208 of orientingelement 204 comprises a secondinflatable member 224 in the embodiment ofFigure 23. Firstinflatable member 220 of orientingelement 204 extends in afirst direction 20 away from the longitudinal axis ofshaft assembly 202. Secondinflatable member 224 of orientingelement 204 extends away from the longitudinal axis ofshaft assembly 202 in asecond direction 22.First direction 20 andsecond direction 22 are represented with arrows inFigure 23. With reference toFigure 23, it will be appreciated thatsecond direction 22 is generally oppositefirst direction 20. InFigure 23, the arrows representingfirst direction 20 andsecond direction 22 are directed about 180 degrees away from one another.
Shaft assembly 202 ofFigure 23 defines afirst aperture 226 and asecond aperture 228. In the embodiment ofFigure 23,first aperture 226 extends away fromcentral lumen 230 in a third direction that is generally perpendicular tofirst direction 20 andsecond direction 22.Second aperture 228 extends away fromcentral lumen 230 in a fourth direction that is generally perpendicular tofirst direction 20 andsecond direction 22. In the embodiment ofFigure 23, the fourth direction is generally opposite to the third direction. In other words, the third direction and the fourth direction are directed about 180 degrees away from each other. The third direction and the fourth direction are both generally orthogonal to the picture plane that the plan view ofFigure 23 is displayed on. It is contemplated that in other embodiments the first andsecond apertures 226, 228 may have a different orientation.
Ahub 236 is fixed to the proximal end ofshaft assembly 202.Hub 236 includes aninflation port 238.Inflation port 238 fluidly communicates with the interior of firstinflatable member 220 and secondinflatable member 224 via inflation lumens defined byshaft assembly 202. Theinflatable members 220, 224 may be inflated by injecting an inflation media intoinflation port 238. Examples of inflation media that may be suitable in some applications include saline, carbon dioxide, and nitrogen.
Orientingcatheter 200 defines aproximal port 232, adistal port 234 and acentral lumen 230 that extends betweenproximal port 232 anddistal port 234. In the embodiment ofFigure 23,proximal port 232 is defined byhub 236 anddistal port 234 is defined byshaft assembly 202. InFigure 23,re-entry device 100 can be seen extending throughproximal port 232,central lumen 230, anddistal port 234. With reference toFigure 23, it will be appreciated thatre-entry device 100 comprises adistal surface 108 and aprobe 106 extending beyonddistal surface 108.Re-entry device 100 may be inserted intoproximal port 232, advanced alongcentral lumen 230, and advanced through any one ofdistal port 234,first aperture 226 andsecond aperture 228.
System 400 ofFigure 23 includes anocclusion catheter 300, an orientingcatheter 200 andre-entry device 100.Occlusion catheter 300 includes aballoon 302 carried by ashaft assembly 304. Ahub 320 is fixed to the proximal end ofshaft assembly 304.Hub 320 defines aninflation port 322 and aproximal aspiration port 324.Shaft assembly 304 ofocclusion catheter 300 defines aninflation lumen 328 and anaspiration lumen 308 that fluidly communicate withinflation port 322 andproximal aspiration port 324, respectively.Aspiration lumen 308 extends betweenproximal aspiration port 324 and adistal aspiration port 306.Inflation lumen 328 extends betweeninflation port 322 and the interior ofballoon 302.
InFigure 23,balloon 302 is shown assuming an inflated shape.Balloon 302 can be selectively inflated by injecting an inflation fluid intoballoon 302 viainflation port 322 andinflation lumen 328. In some useful embodiments,balloon 302 is adapted and dimensioned so as to occlude a blood vessel lumen when it assumes the inflated shape.Balloon 302 may be used to isolate a target volume by occluding the true lumen of the blood vessel. The target volume may include an intrawall space located between the intima and the adventitia of the blood vessel. The target volume may also include a portion of the lumen extending between the balloon and an occlusion that is blocking the lumen of the blood vessel. With the target volume isolated, fluid may be withdrawn from it by drawing the fluid throughdistal aspiration port 306 andaspiration lumen 308 ofocclusion catheter 300. Fluid may also be withdrawn from target volume T by drawing the fluid throughcentral lumen 230 of orientingcatheter 200.
System 400 includes atracking element 402 defining atracking element lumen 404.Shaft assembly 202 of orientingcatheter 200 can be seen extending through trackingelement lumen 404 inFigure 23.Tracking element lumen 404 is configured so that trackingelement 402 is free to slide in distal and proximal axial directions alongshaft assembly 202 of orientingcatheter 200.Occlusion catheter 300 is connected to trackingelement 402 so that axial movement between trackingelement 400 andocclusion catheter 300 is precluded.
Figure 24A is a plan view showing asystem 400 in accordance with the present detailed description.Figure 24B is an enlarged plan view further illustrating a portion ofsystem 400.Figure 24A and Figure 24B may be collectively referred to asFigure 24.System 400 ofFigure 24 includes anocclusion catheter 300, an orientingcatheter 200 and are-entry device 100. Orientingcatheter 200 comprises an orientingelement 204 carried by ashaft assembly 202.Occlusion catheter 300 comprises aballoon 302 carried by ashaft assembly 304.
Shaft assembly 202 of orientingcatheter 200 defines afirst aperture 226, asecond aperture 228, adistal port 234 and acentral lumen 230.Central lumen 230 extends betweendistal port 234 and aproximal port 232 is defined by ahub 236. InFigure 24,re-entry device 100 can be seen extending throughproximal port 232,central lumen 230, anddistal port 234.Re-entry device 100 may be inserted intoproximal port 232, advanced alongcentral lumen 230, and advanced through any one ofdistal port 234,first aperture 226 andsecond aperture 228. With reference toFigure 24, it will be appreciated thatre-entry device 100 comprises adistal surface 108 and aprobe 106 extending beyonddistal surface 108.
Orientingelement 204 of orientingcatheter 200 comprises afirst portion 206 and asecond portion 208. In the embodiment ofFigure 24,first portion 206 of orientingelement 204 comprises a firstinflatable member 220.Second portion 208 of orientingelement 204 comprises a secondinflatable member 224 in the embodiment offigure 24.Shaft assembly 202 defines inflation lumens that fluidly communicate with the interior of firstinflatable member 220, the interior of secondinflatable member 224, andinflation port 238 defined byhub 236. The inflatable members may be inflated by injecting an inflation media intoinflation port 238.
Ahub 320 is fixed to the proximal end ofshaft assembly 304 ofocclusion catheter 300.Hub 320 defines aninflation port 322 and aproximal aspiration port 324.Shaft assembly 304 ofocclusion catheter 300 defines aninflation lumen 328 and anaspiration lumen 308 that fluidly communicate withinflation port 322 andproximal aspiration port 324, respectively.Aspiration lumen 308 extends betweenproximal aspiration port 324 and adistal aspiration port 306.Inflation lumen 328 extends betweeninflation port 322 and the interior ofballoon 302.
InFigure 24,balloon 302 is shown assuming a collapsed and folded state.Balloon 302 can be selectively inflated by injecting an inflation fluid intoballoon 302 viainflation port 322 andinflation lumen 328. In some useful embodiments,balloon 302 is adapted and dimensioned so as to occlude a blood vessel lumen when it assumes the inflated shape.Balloon 302 may be used to isolate a target volume by occluding a lumen segment of a blood vessel. The target volume may include an intrawall space located between the intima and the adventitia of the blood vessel. The target volume may also include a portion of the lumen segment extending between theballoon 302 and an occlusion that is blocking the lumen of the blood vessel. With the target volume isolated, fluid may be withdrawn from it by drawing the fluid throughdistal aspiration port 306 and intoaspiration lumen 308. Fluid may also be withdrawn from the target volume by drawing the fluid throughcentral lumen 230 of orientingcatheter 200 if desired.
System 400 includes atracking element 402 defining atracking element lumen 404.Shaft assembly 202 of orientingcatheter 200 can be seen extending through trackingelement lumen 404 inFigure 24.Tracking element lumen 404 is configured so that trackingelement 402 is free to slide in distal and proximal axial directions alongshaft assembly 202 of orientingcatheter 200.Occlusion catheter 300 and trackingelement 402 comprise amale coupling element 408 and afemale coupling element 406, respectively.Male coupling element 408 andfemale coupling element 406 are adapted and configured to cooperatively form a mechanical connection betweenocclusion catheter 300 and trackingelement 402. In some useful embodiments, this connection is adapted and configured so that axial movement between trackingelement 400 andocclusion catheter 300 is precluded. In the embodiment ofFigure 24,male coupling element 408 includes ashoulder 420 having a proximal facingsurface 424.Female coupling element 406 comprises twotangs 426 in the embodiment ofFigure 24. In other embodiments, thefemale coupling element 406 and themale coupling element 408 may be reversed, with thefemale coupling element 406 provided on theocclusion catheter 300 and themale coupling element 408 provided on thetracking element 402.
Figure 25A is an additional plan view further illustratingsystem 400 shown in the previous figure.Figure 25B is an enlarged plan view further illustrating a portion ofsystem 400. In the embodiment ofFigure 25,male coupling element 408 ofocclusion catheter 300 andfemale coupling element 406 of orientingcatheter 200 are cooperating to form aconnection 440.Connection 440 is adapted and configured so that axial movement between trackingelement 400 andocclusion catheter 300 is precluded in the embodiment ofFigure 25. A proximal edge of eachtang 426 can be seen contacting the proximal-facing surface of theshoulder 420 inFigure 25B.
Figure 26A is a plan view showing asystem 400 in accordance with the present detailed description.Figure 26B is an enlarged plan view further illustrating a portion ofsystem 400.Figure 26A and Figure 26B may be collectively referred to asFigure 26.System 400 may be useful, for example, when establishing a blood flow path between a proximal segment of a blood vessel and a distal segment of a blood vessel that are separated by an occlusion (e.g., the subject matter illustrated in the preceding series of figures).System 400 may also be useful to facilitate visualization of a patient's vasculature using fluoroscopic techniques when conditions arise which interfere with the flow of radiopaque media.
System 400 ofFigure 26 includes anocclusion catheter 300, an orientingcatheter 200 andre-entry device 100. Orientingcatheter 200 ofFigure 26 comprises ashaft assembly 202 and an orientingelement 204 that is carried byshaft assembly 202. Orientingelement 204 of orientingcatheter 200 comprises afirst portion 206 and asecond portion 208. In the embodiment ofFigure 26,first portion 206 of orientingelement 204 comprises a firstinflatable member 220.Second portion 208 of orientingelement 204 comprises a secondinflatable member 224 in the embodiment ofFigure 26. The inflatable members may be inflated by injecting an inflation media into them via inflation lumens defined byshaft assembly 202. The interior of firstinflatable member 220 and the interior of secondinflatable member 224 fluidly communicate with aninflation port 238 defined by ahub 236.
Orientingcatheter 200 defines aproximal port 232, adistal port 234 and acentral lumen 230 that extends betweenproximal port 232 anddistal port 234. In the embodiment ofFigure 26,proximal port 232 is defined byhub 236 anddistal port 234 is defined byshaft assembly 202.Shaft assembly 202 of orientingcatheter 200 defines afirst aperture 226 and asecond aperture 228. InFigure 26,re-entry device 100 can be seen extending throughproximal port 232,central lumen 230, anddistal port 234. With reference toFigure 26, it will be appreciated thatre-entry device 100 comprises adistal surface 108 and aprobe 106 extending beyonddistal surface 108.Re-entry device 100 may be inserted intoproximal port 232, advanced alongcentral lumen 230, and advanced through any one ofdistal port 234,first aperture 226 andsecond aperture 228.
Occlusion catheter 300 ofsystem 400 comprises aballoon 302 carried by ashaft assembly 304. Ahub 320 is fixed to the proximal end ofshaft assembly 304 ofocclusion catheter 300.Hub 320 defines aninflation port 322 and aproximal aspiration port 324.Shaft assembly 304 ofocclusion catheter 300 defines aninflation lumen 328 and anaspiration lumen 308 that fluidly communicate withinflation port 322 andproximal aspiration port 324, respectively.Aspiration lumen 308 extends betweenproximal aspiration port 324 and adistal aspiration port 306.Inflation lumen 328 extends betweeninflation port 322 and the interior ofballoon 302.
InFigure 26,balloon 302 is shown assuming a collapsed and folded state.Balloon 302 can be selectively inflated by injecting an inflation fluid intoballoon 302 viainflation port 322 andinflation lumen 328. In some useful embodiments,balloon 302 is adapted and dimensioned so as to occlude a blood vessel lumen when it assumes the inflated shape.Balloon 302 may be used to isolate a target volume by occluding a lumen segment of a blood vessel. The target volume may include an intrawall space located between the intima and the adventitia of the blood vessel. The target volume may also include a portion of the lumen segment extending between the balloon and an occlusion that is blocking the lumen of the blood vessel. With the target volume isolated, fluid may be withdrawn from it by drawing the fluid throughdistal aspiration port 306 and intoaspiration lumen 308. Fluid may also be withdrawn from the target volume by drawing the fluid throughcentral lumen 230 of orientingcatheter 200 if desired.
System 400 includes atracking element 402 defining atracking element lumen 404.Shaft assembly 202 of orientingcatheter 200 can be seen extending through trackingelement lumen 404 inFigure 26.Tracking element lumen 404 is configured so that trackingelement 402 is free to slide in distal and proximal axial directions alongshaft assembly 202 of orientingcatheter 200.Occlusion catheter 300 and trackingelement 402 comprise amale coupling element 408 and afemale coupling element 406, respectively.Male coupling element 408 andfemale coupling element 406 are adapted and configured to cooperatively form a mechanical connection betweenocclusion catheter 300 and trackingelement 402. In some useful embodiments, this connection is adapted and configured so that axial movement between trackingelement 400 andocclusion catheter 300 is precluded. In the embodiment ofFigure 26,female coupling element 406 includes ashoulder 420 having a distal facingsurface 422.Male coupling element 408 comprises twofingers 428 in the embodiment ofFigure 26. In other embodiments, thefemale coupling element 406 and themale coupling element 408 may be reversed, with thefemale coupling element 406 provided on theocclusion catheter 300 and themale coupling element 408 provided on thetracking element 402.
Figure 27A is an additional plan view further illustratingsystem 400 shown in the previous figure.Figure 27B is an enlarged plan view further illustrating a portion ofsystem 400.Male coupling element 408 ofocclusion catheter 300 andfemale coupling element 406 of orientingcatheter 200 are cooperating to form aconnection 440 in the embodiment ofFigure 27. In the embodiment ofFigure 27, this connection is adapted and configured so that axial movement between trackingelement 400 andocclusion catheter 300 is precluded. A proximal edge of eachfinger 428 can be seen contacting the distal-facingsurface 422 of the shoulder inFigure 27B.
Figure 28A is a stylized pictorial view of ablood vessel 30 having awall 40 including anadventitia 42, a media M, and anintima 44. In the embodiment ofFigure 28A, an orientingelement 202 of an orientingcatheter 200 is disposed in an intrawall space S located between theintima 44 and theadventitia 42 ofblood vessel 30. In the embodiment ofFigure 28A, a portion ofintima 44 has become separated from the other layers ofblood vessel wall 40. This situation may occur, for example, when a physician has passed one or more prolapsed guidewires between the intima and the adventitia.
Figure 28B is an additional stylized pictorial view ofblood vessel 30 shown in the previous figure. By comparingFigure 28B withFigure 28A, it will be appreciated that the volume of intrawall space S has been reduced substantially.Intima 44 can be seen contacting orientingelement 202 of orientingcatheter 200 inFigure 28B. In some useful methods, the volume of an intrawall space S may be reduced by withdrawing fluid from the intrawall space. Fluid may be withdrawn from intrawall space S by drawing the fluid throughcentral lumen 230 of orientingcatheter 200. Fluid may also be withdrawn from intrawall space S by drawing the fluid through the aspiration lumen of anocclusion catheter 300 in accordance with this detailed description.
Withdrawing fluid from intrawall space S may reduce the pressure inside the intrawall space S to a pressure less than the pressure in the true lumen distal of the occlusion (e.g., below atrial pressure PA) so that pressure inside the true lumen distal of the occlusion presses theintima 44 of theblood vessel 30 against the orientingelement 202 of the orientingcatheter 200. In other words, the pressure on the intrawall side of theintima 44 may be less than the pressure on the true lumen side of theintima 44 distal of the occlusion. Withdrawing fluid from the intrawall space S may be particularly beneficial when the blood vessel wall has been dissected as one or more prolapsed guidewires have passed through it. More particularly, withdrawing fluid from the intrawall space S may facilitate the use of fluoroscopic imaging techniques when an elongated dissection is interfering with the flow of radiopaque imaging media into a lumen segment of the blood vessel. Additionally, withdrawing fluid from the intrawall space S may facilitate the piercing ofintima 44 to complete a blood flow path extending between a proximal lumen segment and a distal lumen segment of the blood vessel.
From the foregoing, it will be apparent to those skilled in the art that the present disclosure provides, in exemplary non-limiting embodiments, devices and methods for the treatment of chronic total occlusions. Further, those skilled in the art will recognize that aspects of the present disclosure may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departures in form and detail may be made without departing from the scope of the present disclosure as described in the appended claims.

Claims

A system for treating a blood vessel (30) including a blood vessel wall (40) defining a blood vessel lumen (34), the blood vessel lumen (34) being at least partially obstructed by an occlusion (32), the occlusion (32) dividing the lumen (34) into a proximal lumen segment (36) and a distal lumen segment (38), the system comprising:
an occlusion catheter (300) comprising a balloon (302); the occlusion catheter (300) defining an inflation lumen (328) disposed in fluid communication with an interior of the balloon (302) so that the balloon (302) can be selectively inflated by injecting an inflation fluid through the inflation lumen (328);
the balloon (302), when in an inflated state, being sized so as to occlude the blood vessel lumen (34) to isolate a target volume (T) defined by blood vessel tissues;
the occlusion catheter (300) defining an aspiration lumen (308) disposed in fluid communication with a distal port (306) positioned so that fluid can be withdrawn from the target volume (T) and into the aspiration lumen (308),characterized in that:
the system further comprises an orienting catheter (200) including an orienting catheter shaft (202) carrying an orienting element (204) and a tracking element (402) advanceable along the orienting catheter shaft (202); andin that:
the occlusion catheter further comprises a coupling element (408; 406) configured to engage a complementary coupling element (406; 408) of the tracking element (402) to form a connection (440) there between.
The system of claim 1, wherein the tracking element (402) includes a tracking element lumen (404) through which the orienting catheter shaft (202) extends through.
The system of claim 2, wherein the tracking element lumen (404) is dimensioned so that the tracking element (402) is free to slide in proximal and distal axial directions along the orienting catheter shaft (202).
The system of claim 1, wherein the coupling element (408; 406) of the occlusion catheter (300) is disposed distal of the balloon (302).
The system of claim 1, wherein the orienting element (204) comprises a first inflatable member (220) and a second inflatable member (224), the first inflatable member (220) extending from the orienting catheter shaft (202) in a first direction (20), the second inflatable member (224) extending from the orienting catheter shaft (202) in a second direction (22), the second direction (22) being substantially opposite the first direction (20).
The system of claim 5, wherein the first inflatable member (220), the second inflatable member (224), and the orienting catheter shaft (202) are monolithic.